I've stumbled on the こおんな ( 小女 ) word, which is labeled as archaic. However, of the three meanings given (small woman, young woman, young maid), the third one is additionally labeled as "sensitive".
I'm wondering why, as none of the websites I found mentioning it say why (jisho.org, japandict.com, and a few others which I didn't remember)
I'm guessing it might have sexual connotations (like, maids having to service their master), but I'd rather get the real explanation than a mere guess.